Entries Tagged "Microsoft"

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Microsoft Signing Key Stolen by Chinese

A bunch of networks, including US Government networks, have been hacked by the Chinese. The hackers used forged authentication tokens to access user email, using a stolen Microsoft Azure account consumer signing key. Congress wants answers. The phrase “negligent security practices” is being tossed about—and with good reason. Master signing keys are not supposed to be left around, waiting to be stolen.

Actually, two things went badly wrong here. The first is that Azure accepted an expired signing key, implying a vulnerability in whatever is supposed to check key validity. The second is that this key was supposed to remain in the the system’s Hardware Security Module—and not be in software. This implies a really serious breach of good security practice. The fact that Microsoft has not been forthcoming about the details of what happened tell me that the details are really bad.

I believe this all traces back to SolarWinds. In addition to Russia inserting malware into a SolarWinds update, China used a different SolarWinds vulnerability to break into networks. We know that Russia accessed Microsoft source code in that attack. I have heard from informed government officials that China used their SolarWinds vulnerability to break into Microsoft and access source code, including Azure’s.

I think we are grossly underestimating the long-term results of the SolarWinds attacks. That backdoored update was downloaded by over 14,000 networks worldwide. Organizations patched their networks, but not before Russia—and others—used the vulnerability to enter those networks. And once someone is in a network, it’s really hard to be sure that you’ve kicked them out.

Sophisticated threat actors are realizing that stealing source code of infrastructure providers, and then combing that code for vulnerabilities, is an excellent way to break into organizations who use those infrastructure providers. Attackers like Russia and China—and presumably the US as well—are prioritizing going after those providers.

News articles.

EDITED TO ADD: Commentary:

This is from Microsoft’s explanation. The China attackers “acquired an inactive MSA consumer signing key and used it to forge authentication tokens for Azure AD enterprise and MSA consumer to access OWA and Outlook.com. All MSA keys active prior to the incident—including the actor-acquired MSA signing key—have been invalidated. Azure AD keys were not impacted. Though the key was intended only for MSA accounts, a validation issue allowed this key to be trusted for signing Azure AD tokens. The actor was able to obtain new access tokens by presenting one previously issued from this API due to a design flaw. This flaw in the GetAccessTokenForResourceAPI has since been fixed to only accept tokens issued from Azure AD or MSA respectively. The actor used these tokens to retrieve mail messages from the OWA API.”

Posted on August 7, 2023 at 7:03 AMView Comments

Redacting Documents with a Black Sharpie Doesn’t Work

We have learned this lesson again:

As part of the FTC v. Microsoft hearing, Sony supplied a document from PlayStation chief Jim Ryan that includes redacted details on the margins Sony shares with publishers, its Call of Duty revenues, and even the cost of developing some of its games.

It looks like someone redacted the documents with a black Sharpie ­ but when you scan them in, it’s easy to see some of the redactions. Oops.

I don’t particularly care about the redacted information, but it’s there in the article.

Posted on June 29, 2023 at 10:37 AMView Comments

Microsoft Secure Boot Bug

Microsoft is currently patching a zero-day Secure-Boot bug.

The BlackLotus bootkit is the first-known real-world malware that can bypass Secure Boot protections, allowing for the execution of malicious code before your PC begins loading Windows and its many security protections. Secure Boot has been enabled by default for over a decade on most Windows PCs sold by companies like Dell, Lenovo, HP, Acer, and others. PCs running Windows 11 must have it enabled to meet the software’s system requirements.

Microsoft says that the vulnerability can be exploited by an attacker with either physical access to a system or administrator rights on a system. It can affect physical PCs and virtual machines with Secure Boot enabled.

That’s important. This is a nasty vulnerability, but it takes some work to exploit it.

The problem with the patch is that it breaks backwards compatibility: “…once the fixes have been enabled, your PC will no longer be able to boot from older bootable media that doesn’t include the fixes.”


Not wanting to suddenly render any users’ systems unbootable, Microsoft will be rolling the update out in phases over the next few months. The initial version of the patch requires substantial user intervention to enable—you first need to install May’s security updates, then use a five-step process to manually apply and verify a pair of “revocation files” that update your system’s hidden EFI boot partition and your registry. These will make it so that older, vulnerable versions of the bootloader will no longer be trusted by PCs.

A second update will follow in July that won’t enable the patch by default but will make it easier to enable. A third update in “first quarter 2024” will enable the fix by default and render older boot media unbootable on all patched Windows PCs. Microsoft says it is “looking for opportunities to accelerate this schedule,” though it’s unclear what that would entail.

So it’ll be almost a year before this is completely fixed.

Posted on May 17, 2023 at 7:01 AMView Comments

Critical Microsoft Code-Execution Vulnerability

A critical code-execution vulnerability in Microsoft Windows was patched in September. It seems that researchers just realized how serious it was (and is):

Like EternalBlue, CVE-2022-37958, as the latest vulnerability is tracked, allows attackers to execute malicious code with no authentication required. Also, like EternalBlue, it’s wormable, meaning that a single exploit can trigger a chain reaction of self-replicating follow-on exploits on other vulnerable systems. The wormability of EternalBlue allowed WannaCry and several other attacks to spread across the world in a matter of minutes with no user interaction required.

But unlike EternalBlue, which could be exploited when using only the SMB, or server message block, a protocol for file and printer sharing and similar network activities, this latest vulnerability is present in a much broader range of network protocols, giving attackers more flexibility than they had when exploiting the older vulnerability.


Microsoft fixed CVE-2022-37958 in September during its monthly Patch Tuesday rollout of security fixes. At the time, however, Microsoft researchers believed the vulnerability allowed only the disclosure of potentially sensitive information. As such, Microsoft gave the vulnerability a designation of “important.” In the routine course of analyzing vulnerabilities after they’re patched, Palmiotti discovered it allowed for remote code execution in much the way EternalBlue did. Last week, Microsoft revised the designation to critical and gave it a severity rating of 8.1, the same given to EternalBlue.

Posted on December 22, 2022 at 7:01 AMView Comments

Finding Vulnerabilities in Open Source Projects

The Open Source Security Foundation announced $10 million in funding from a pool of tech and financial companies, including $5 million from Microsoft and Google, to find vulnerabilities in open source projects:

The “Alpha” side will emphasize vulnerability testing by hand in the most popular open-source projects, developing close working relationships with a handful of the top 200 projects for testing each year. “Omega” will look more at the broader landscape of open source, running automated testing on the top 10,000.

This is an excellent idea. This code ends up in all sorts of critical applications.

Log4j would be a prototypical vulnerability that the Alpha team might look for ­—an unknown problem in a high-impact project that automated tools would not be able to pick up before a human discovered it. The goal is not to use the personnel engaged with Alpha to replicate dependency analysis, for example.

Posted on February 2, 2022 at 9:58 AMView Comments

Is Microsoft Stealing People’s Bookmarks?

I received email from two people who told me that Microsoft Edge enabled synching without warning or consent, which means that Microsoft sucked up all of their bookmarks. Of course they can turn synching off, but it’s too late.

Has this happened to anyone else, or was this user error of some sort? If this is real, can some reporter write about it?

(Not that “user error” is a good justification. Any system where making a simple mistake means that you’ve forever lost your privacy isn’t a good one. We see this same situation with sharing contact lists with apps on smartphones. Apps will repeatedly ask, and only need you to accidentally click “okay” once.)

EDITED TO ADD: It’s actually worse than I thought. Edge urges users to store passwords, ID numbers, and even passport numbers, all of which get uploaded to Microsoft by default when synch is enabled.

Posted on November 17, 2021 at 7:53 AMView Comments

More Russian SVR Supply-Chain Attacks

Microsoft is reporting that the same attacker that was behind the SolarWinds breach—the Russian SVR, which Microsoft is calling Nobelium—is continuing with similar supply-chain attacks:

Nobelium has been attempting to replicate the approach it has used in past attacks by targeting organizations integral to the global IT supply chain. This time, it is attacking a different part of the supply chain: resellers and other technology service providers that customize, deploy and manage cloud services and other technologies on behalf of their customers. We believe Nobelium ultimately hopes to piggyback on any direct access that resellers may have to their customers’ IT systems and more easily impersonate an organization’s trusted technology partner to gain access to their downstream customers. We began observing this latest campaign in May 2021 and have been notifying impacted partners and customers while also developing new technical assistance and guidance for the reseller community. Since May, we have notified more than 140 resellers and technology service providers that have been targeted by Nobelium. We continue to investigate, but to date we believe as many as 14 of these resellers and service providers have been compromised. Fortunately, we have discovered this campaign during its early stages, and we are sharing these developments to help cloud service resellers, technology providers, and their customers take timely steps to help ensure Nobelium is not more successful.

Posted on October 28, 2021 at 6:12 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.